Automatic drifting valve



Patented Mar. 13, 1951 UNITED STATES PATENT ori ice AUTOMATIC DRIFTING VALVE- namuna P. Kelly, Chica'goJll. Application February 20,-.1948, Serial No. 9,807

1 Claim. (011121-9134) My invention relates to improvements in auto- 1 formation of a vacuum as a result of the drifting movement of the locomotive with the throttle closed, which vacuum unless prevented, would cause hot gases to be drawn in from the front end of the smoke box of the locomotive through exhaust passages.

I propose to apply to the exhaust side of the main steam valve at any suitable point, a drifting valve which will automatically, when the throttle is closed and steam pressure closed off, admit air to the exhaust side of the engine thus preventing the formation of any such vacuum.

My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

Figure 1 is a section through the valve shaft and part of the cylinder and piston showing my drifting valve in elevation;

Figure 2 is a cylinder section on an enlarged scale, of my valve.

Like parts are indicated by like characters in the drawings.

I is the cylinder; 2 the piston; 3 is the cylinder ports which respectively connect the valve chest with each end of the cylinder. 4 is the valve chest which contains ported valve seat sleeves 5, 6. These ports being in register with the ports 3, 3. l is a spool valve having enlarged heads 8, 9 adapted to travel in the sleeves 5, 6 to open and close the ports in those sleeves. I is the valve stem. H a cap closing the valve chest on the high pressure side and recessed as at l2 to receive packing not here shown as it forms no part of my invention. I3 is a cap closing the opposite end of the valve chest. I4 is the high pressure side of the valve chest and I the high pressure steam pipe from the boiler. The exhaust from the low pressure side of the valve chest It is not illustrated as it also forms no part of my invention.

The cap I3 is centrally apertured a at H. Closing that aperture is a ball ring l8 held in place on the cap or valve chest head I 3 by cap screws I9. Extending outwardly from the ball ring 58 are a series of supporting brackets which carry a collar 2| to which is bolted the apertured ring 22 by means of bolts 23. The apertured ring 22 carries the drifting valve cylinder 24 flanged as indicated to engage the ring 22. 25 is packing within the cylinder- 2ljadapted to be eem ess d by the gland 26 and cap screws 21.

28- is a hollow piston contained within the cylinder 24- closed at the outboard end. This piston carries a valve disc 29 about the periphery ,of which is a valve ring 30. i I

Extending outwardly from the ball rin g were a series of lugs 3| which support a shield 32; there being apertures between the shield 32, the lugs 3| and the ball ring l8 to contain netting or screening or other material to prevent the entrance into the valve chest of foreign material.

33 is a spring fitted at one end of the shield 32 and the other end of the hollow piston 28. 34 is a pipe that leads from the end of the cylinder 24 to the high pressure side of the valve chest. 35 are studs threaded in the collar 22 which may be screwed inwardly if desired to overcome the spring pressure 33 and seat the valve 29, 30.

It will be understood that under ordinary operating conditions when steam is applied to the high pressure side of the valve chest I 4 through the steam pipe I 5, the steam passes through the pipe 34 into the drifting valve cylinder '24 through the passage of piston 28, overcoming the spring 33 closing the aperture through the ball ring I8. Under these circumstances, the usual valve movements take place; the locomotive operates in the usual manner because we have on one side of the piston 28, high pressure steam direct from the boiler and on the other side of the piston only exhaust pressure which is little if any above atmospheric.

If now, the engineer, closes the throttle, shutting olf the steam supply to the high pressure side of the valve chest and the engine drifts along under the weight of the train in the usual manner, since no steam is being fed to the piston through the valve chest and since the piston continues to work back and forth and the steam valve continues its usual cycle, a vacuum is set up in the exhaust side of the valve chest and since the exhaust side of the valve chest is directly connected through the exhaust nozzle (not shown), through the smoke box at the forward end of the boiler, this vacuum will draw hot gas, soot, cinders, etc., through the valve chest, thus causing a very dangerous and unsatisfactory condition. However, when the engineer turns off the steam by closing the throttle, the same time pressure drops on the outboard end of the piston 28 the spring 33 immediately opens valve making a direct passage from the exhaust side of the valve chest to the atmosphere and so this vacuum is effectively avoided and this situation prevails until the engineer again opens th throttle when immediately, the drifting valve closes and the engineer operates in the usual manner.

The solepurpose of the studs 35 is to provide a positive closure for the valve chest, if that should be necessary or desirable, as for instance in connection with hydrostatic tests and the like.

Althrough I have shown an operative form of my invention. at will "be recognized that many changesi-in the term, {shape and arrangement of parts can be made without departing from the spirit of the invention, and my showing is therefore to be taken as, in a sense, diagrammatic.

I claim:

In combination, a valve chest foristeamlocomotives and the like, a reciprocating cylindrical valve, dividing the chest into high-pressure steam and low pressure exhaust sections, an-.- aperture in the wall of the chest between theexhau'st section and the, outer atmosphere, arbracket mask- "carrying the sleeve valve, yielding means tending REFERENCES CITED The following references are of record in the file of this patent:

:UNITED STATES PATENTS Number Name Date 1%2301 lBrutal-itch Jan. 5, 1904 'I8Q,8,66 Cunningham Jan. 24, 1905 839,912 Whelan Jan. 1, 1907 1,116,380 Buckbee NOV. 10, 1914 11 221,098 "-VmQent m. Unwed ;'May;22, 1917 31,353,296 Whelan ..,i i flats-21,1920 11,510,385? elietart Oct-'1, V1924 lflQfifiZfi Busch et;a1.. Mar. 26, 1929 "2,096,408 Richardson Oct. 19, 1937 2.135.952 B10811 et a1. Nov. ,15, .1938 

